Whale oil is a type of oil that was historically extracted from the blubber of whales. It was commonly used in the 18th and 19th centuries for lighting lamps, making soap, and as a lubricant. The oil was prized for its ability to burn brightly and cleanly, making it a popular choice before the advent of kerosene and electricity. The hunting of whales for their oil led to significant declines in whale populations, prompting conservation efforts. Today, the use of whale oil is largely banned in many countries due to ethical concerns and the protection of whale species.